Epithelial Tissue

Question 1

transitional epithelium

Answer 1

line much of urinary tract; allows for distension as bladder fills

Question 2

basal pole

Answer 2

region of cell contacting the basement membrane (ECM)

Question 3

basement membranes

Answer 3

specialized sheet of ECM to which the epithelium anchors

Question 4

tight junctions (occludens)

Answer 4

seals neighboring cell membranes by forming a band encircling each cell

Question 5

tight junctions ensure _

Answer 5

molecules crossing the epithelium go through the cell and not between them; prevents movement of membrane proteins

Question 6

adherens junctions

Answer 6

located right below and reinforce tight junctions

Question 7

columnar epithelium

Answer 7

provide protection

Question 8

squamous epithelium

Answer 8

provide area for exchange/diffusion

Question 9

cuboidal epithelium

Answer 9

function in protection, secretion, absorption

Question 10

simple cuboidal is found in _

Answer 10

renal collecting tubule, mesothelium covering ovary, large thyroid particle

Question 11

simple squamous found in _

Answer 11

outer wall of intestine, inner surface of cornea, renal loops of henle

Question 12

simple columnar found in _

Answer 12

renal collecting duct, lining of gallbladder, oviduct lining

Question 13

desmosomes

Answer 13

provide mechanical stability and firm adhesion among cells

Question 14

hemidesmosome

Answer 14

anchors cell to basal lamina; mediated by integrins and collagen

Question 15

gap junctions

Answer 15

mediate communication rather than adhesion using connexin molecules

Question 16

Charcot-Marie-Tooth Disease

Answer 16

linked to mutation of connexins in the myelin sheath, leading to nerve problems and atrophy of innervated muscles

Question 17

microvilli

Answer 17

present on epithelial cells specialized for absorption (small intestine)

Question 18

microvilli are composed of _

Answer 18

bundles of actin filaments

Question 19

stereocilia

Answer 19

longer and less motile than microvilli; can be absorptive or sensory (inner ear)

Question 20

cilia

Answer 20

long projecting structures made of MTs

Question 21

cilia structure

Answer 21

9 + 2 doublets of MTs (axoneme) –> anchored to basal bodies (triplets)

Question 22

goblet cell

Answer 22

unicellular gland abundant in the lining of the small intestine and respiratory tract that secretes lubricating mucus

Question 23

exocrine glands

Answer 23

maintain connection with surface epithelium and form tubular ducts that secrete material

Question 24

endocrine glands

Answer 24

lose connection with surface epithelium and have no ducts –> adjacent capillaries absorb secreted products and transport them in the blood to targets

Question 25

merocrine secretion

Answer 25

exocytosis at apical membrane

Question 26

holocrine secretion

Answer 26

complete disruption of cell releasing product into gland lumen

Question 27

apocrine secretion

Answer 27

product accumulates at apical end and extruded with some cytoplasm and membrane